In the field of retaining walls, various combinations of planks, crossbars and anchors have longed been used. To retain embankments or property along a waterfront, bulkhead walls of steel or timber were used commonly. Such materials are disfavored now for many reasons, and so, a need exists for an improved retaining wall member.
Timber and steel bulkheads are costly, and there is a concern about the continued availability of those materials. Also, heavy equipment and skilled workers are needed to install steel or timber wall members. These materials corrode and decay.
Timber can be treated to delay rot. However, known wood treatments involve chemicals that environmental and labor agencies presently regulate and even prohibit. Steel, even coated steel, will corrode in marine use. For example, equipment aboard ships leak electrical charges that are conducted through ions in the water to the grounded steel members. This cathodic reaction hastens the deterioration of steel. To avoid these problems, polymeric material can be fabricated into retaining wall members. When using polymeric planks or members, their structure dictates their strength and loading capacity.